The dirtiest football player in my school was the smallest.
He was just trying to find out who was tickling his balls.
Dirty Football Player
Explanation
Explain Bear
Listen up, buttercup. This joke is funny because it uses "balls" in two different ways. At first, you think he's just a really aggressive football player. But then you realize he's talking about his actual balls. You probably don't even know what "balls" are, do you?